aboutsummaryrefslogtreecommitdiffstats
path: root/arch/ppc/kernel/module.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/ppc/kernel/module.c')
-rw-r--r--arch/ppc/kernel/module.c320
1 files changed, 0 insertions, 320 deletions
diff --git a/arch/ppc/kernel/module.c b/arch/ppc/kernel/module.c
deleted file mode 100644
index 92f4e5f64f02..000000000000
--- a/arch/ppc/kernel/module.c
+++ /dev/null
@@ -1,320 +0,0 @@
1/* Kernel module help for PPC.
2 Copyright (C) 2001 Rusty Russell.
3
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 2 of the License, or
7 (at your option) any later version.
8
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
13
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software
16 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17*/
18#include <linux/module.h>
19#include <linux/moduleloader.h>
20#include <linux/elf.h>
21#include <linux/vmalloc.h>
22#include <linux/fs.h>
23#include <linux/string.h>
24#include <linux/kernel.h>
25#include <linux/cache.h>
26
27#if 0
28#define DEBUGP printk
29#else
30#define DEBUGP(fmt , ...)
31#endif
32
33LIST_HEAD(module_bug_list);
34
35void *module_alloc(unsigned long size)
36{
37 if (size == 0)
38 return NULL;
39 return vmalloc(size);
40}
41
42/* Free memory returned from module_alloc */
43void module_free(struct module *mod, void *module_region)
44{
45 vfree(module_region);
46 /* FIXME: If module_region == mod->init_region, trim exception
47 table entries. */
48}
49
50/* Count how many different relocations (different symbol, different
51 addend) */
52static unsigned int count_relocs(const Elf32_Rela *rela, unsigned int num)
53{
54 unsigned int i, j, ret = 0;
55
56 /* Sure, this is order(n^2), but it's usually short, and not
57 time critical */
58 for (i = 0; i < num; i++) {
59 for (j = 0; j < i; j++) {
60 /* If this addend appeared before, it's
61 already been counted */
62 if (ELF32_R_SYM(rela[i].r_info)
63 == ELF32_R_SYM(rela[j].r_info)
64 && rela[i].r_addend == rela[j].r_addend)
65 break;
66 }
67 if (j == i) ret++;
68 }
69 return ret;
70}
71
72/* Get the potential trampolines size required of the init and
73 non-init sections */
74static unsigned long get_plt_size(const Elf32_Ehdr *hdr,
75 const Elf32_Shdr *sechdrs,
76 const char *secstrings,
77 int is_init)
78{
79 unsigned long ret = 0;
80 unsigned i;
81
82 /* Everything marked ALLOC (this includes the exported
83 symbols) */
84 for (i = 1; i < hdr->e_shnum; i++) {
85 /* If it's called *.init*, and we're not init, we're
86 not interested */
87 if ((strstr(secstrings + sechdrs[i].sh_name, ".init") != 0)
88 != is_init)
89 continue;
90
91 /* We don't want to look at debug sections. */
92 if (strstr(secstrings + sechdrs[i].sh_name, ".debug") != 0)
93 continue;
94
95 if (sechdrs[i].sh_type == SHT_RELA) {
96 DEBUGP("Found relocations in section %u\n", i);
97 DEBUGP("Ptr: %p. Number: %u\n",
98 (void *)hdr + sechdrs[i].sh_offset,
99 sechdrs[i].sh_size / sizeof(Elf32_Rela));
100 ret += count_relocs((void *)hdr
101 + sechdrs[i].sh_offset,
102 sechdrs[i].sh_size
103 / sizeof(Elf32_Rela))
104 * sizeof(struct ppc_plt_entry);
105 }
106 }
107
108 return ret;
109}
110
111int module_frob_arch_sections(Elf32_Ehdr *hdr,
112 Elf32_Shdr *sechdrs,
113 char *secstrings,
114 struct module *me)
115{
116 unsigned int i;
117
118 /* Find .plt and .init.plt sections */
119 for (i = 0; i < hdr->e_shnum; i++) {
120 if (strcmp(secstrings + sechdrs[i].sh_name, ".init.plt") == 0)
121 me->arch.init_plt_section = i;
122 else if (strcmp(secstrings + sechdrs[i].sh_name, ".plt") == 0)
123 me->arch.core_plt_section = i;
124 }
125 if (!me->arch.core_plt_section || !me->arch.init_plt_section) {
126 printk("Module doesn't contain .plt or .init.plt sections.\n");
127 return -ENOEXEC;
128 }
129
130 /* Override their sizes */
131 sechdrs[me->arch.core_plt_section].sh_size
132 = get_plt_size(hdr, sechdrs, secstrings, 0);
133 sechdrs[me->arch.init_plt_section].sh_size
134 = get_plt_size(hdr, sechdrs, secstrings, 1);
135 return 0;
136}
137
138int apply_relocate(Elf32_Shdr *sechdrs,
139 const char *strtab,
140 unsigned int symindex,
141 unsigned int relsec,
142 struct module *module)
143{
144 printk(KERN_ERR "%s: Non-ADD RELOCATION unsupported\n",
145 module->name);
146 return -ENOEXEC;
147}
148
149static inline int entry_matches(struct ppc_plt_entry *entry, Elf32_Addr val)
150{
151 if (entry->jump[0] == 0x3d600000 + ((val + 0x8000) >> 16)
152 && entry->jump[1] == 0x396b0000 + (val & 0xffff))
153 return 1;
154 return 0;
155}
156
157/* Set up a trampoline in the PLT to bounce us to the distant function */
158static uint32_t do_plt_call(void *location,
159 Elf32_Addr val,
160 Elf32_Shdr *sechdrs,
161 struct module *mod)
162{
163 struct ppc_plt_entry *entry;
164
165 DEBUGP("Doing plt for call to 0x%x at 0x%x\n", val, (unsigned int)location);
166 /* Init, or core PLT? */
167 if (location >= mod->module_core
168 && location < mod->module_core + mod->core_size)
169 entry = (void *)sechdrs[mod->arch.core_plt_section].sh_addr;
170 else
171 entry = (void *)sechdrs[mod->arch.init_plt_section].sh_addr;
172
173 /* Find this entry, or if that fails, the next avail. entry */
174 while (entry->jump[0]) {
175 if (entry_matches(entry, val)) return (uint32_t)entry;
176 entry++;
177 }
178
179 /* Stolen from Paul Mackerras as well... */
180 entry->jump[0] = 0x3d600000+((val+0x8000)>>16); /* lis r11,sym@ha */
181 entry->jump[1] = 0x396b0000 + (val&0xffff); /* addi r11,r11,sym@l*/
182 entry->jump[2] = 0x7d6903a6; /* mtctr r11 */
183 entry->jump[3] = 0x4e800420; /* bctr */
184
185 DEBUGP("Initialized plt for 0x%x at %p\n", val, entry);
186 return (uint32_t)entry;
187}
188
189int apply_relocate_add(Elf32_Shdr *sechdrs,
190 const char *strtab,
191 unsigned int symindex,
192 unsigned int relsec,
193 struct module *module)
194{
195 unsigned int i;
196 Elf32_Rela *rela = (void *)sechdrs[relsec].sh_addr;
197 Elf32_Sym *sym;
198 uint32_t *location;
199 uint32_t value;
200
201 DEBUGP("Applying ADD relocate section %u to %u\n", relsec,
202 sechdrs[relsec].sh_info);
203 for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rela); i++) {
204 /* This is where to make the change */
205 location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
206 + rela[i].r_offset;
207 /* This is the symbol it is referring to. Note that all
208 undefined symbols have been resolved. */
209 sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
210 + ELF32_R_SYM(rela[i].r_info);
211 /* `Everything is relative'. */
212 value = sym->st_value + rela[i].r_addend;
213
214 switch (ELF32_R_TYPE(rela[i].r_info)) {
215 case R_PPC_ADDR32:
216 /* Simply set it */
217 *(uint32_t *)location = value;
218 break;
219
220 case R_PPC_ADDR16_LO:
221 /* Low half of the symbol */
222 *(uint16_t *)location = value;
223 break;
224
225 case R_PPC_ADDR16_HA:
226 /* Sign-adjusted lower 16 bits: PPC ELF ABI says:
227 (((x >> 16) + ((x & 0x8000) ? 1 : 0))) & 0xFFFF.
228 This is the same, only sane.
229 */
230 *(uint16_t *)location = (value + 0x8000) >> 16;
231 break;
232
233 case R_PPC_REL24:
234 if ((int)(value - (uint32_t)location) < -0x02000000
235 || (int)(value - (uint32_t)location) >= 0x02000000)
236 value = do_plt_call(location, value,
237 sechdrs, module);
238
239 /* Only replace bits 2 through 26 */
240 DEBUGP("REL24 value = %08X. location = %08X\n",
241 value, (uint32_t)location);
242 DEBUGP("Location before: %08X.\n",
243 *(uint32_t *)location);
244 *(uint32_t *)location
245 = (*(uint32_t *)location & ~0x03fffffc)
246 | ((value - (uint32_t)location)
247 & 0x03fffffc);
248 DEBUGP("Location after: %08X.\n",
249 *(uint32_t *)location);
250 DEBUGP("ie. jump to %08X+%08X = %08X\n",
251 *(uint32_t *)location & 0x03fffffc,
252 (uint32_t)location,
253 (*(uint32_t *)location & 0x03fffffc)
254 + (uint32_t)location);
255 break;
256
257 case R_PPC_REL32:
258 /* 32-bit relative jump. */
259 *(uint32_t *)location = value - (uint32_t)location;
260 break;
261
262 default:
263 printk("%s: unknown ADD relocation: %u\n",
264 module->name,
265 ELF32_R_TYPE(rela[i].r_info));
266 return -ENOEXEC;
267 }
268 }
269 return 0;
270}
271
272int module_finalize(const Elf_Ehdr *hdr,
273 const Elf_Shdr *sechdrs,
274 struct module *me)
275{
276 char *secstrings;
277 unsigned int i;
278
279 me->arch.bug_table = NULL;
280 me->arch.num_bugs = 0;
281
282 /* Find the __bug_table section, if present */
283 secstrings = (char *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
284 for (i = 1; i < hdr->e_shnum; i++) {
285 if (strcmp(secstrings+sechdrs[i].sh_name, "__bug_table"))
286 continue;
287 me->arch.bug_table = (void *) sechdrs[i].sh_addr;
288 me->arch.num_bugs = sechdrs[i].sh_size / sizeof(struct bug_entry);
289 break;
290 }
291
292 /*
293 * Strictly speaking this should have a spinlock to protect against
294 * traversals, but since we only traverse on BUG()s, a spinlock
295 * could potentially lead to deadlock and thus be counter-productive.
296 */
297 list_add(&me->arch.bug_list, &module_bug_list);
298
299 return 0;
300}
301
302void module_arch_cleanup(struct module *mod)
303{
304 list_del(&mod->arch.bug_list);
305}
306
307struct bug_entry *module_find_bug(unsigned long bugaddr)
308{
309 struct mod_arch_specific *mod;
310 unsigned int i;
311 struct bug_entry *bug;
312
313 list_for_each_entry(mod, &module_bug_list, bug_list) {
314 bug = mod->bug_table;
315 for (i = 0; i < mod->num_bugs; ++i, ++bug)
316 if (bugaddr == bug->bug_addr)
317 return bug;
318 }
319 return NULL;
320}
generated by cgit v1.2.2 (git 2.25.0) at 2024-12-15 18:49:05 -0500